The invention relates to a motor-fan unit particularly for a heating and/or air conditioning apparatus, in particular for a motor vehicle.
For such an application, it is known practice to use a motor-fan unit of the type comprising a casing, a turbine housed in the casing to generate an air flow therein, a motor for driving the turbine, a support for the motor also forming a cover that closes off the casing on one side thereof, and a module for controlling the motor to allow the motor speed to be varied as needed.
One problem to be solved is that of cooling the motor control modules. It is known practice for one or more radiators to be associated with the control module for this purpose in order to dissipate the heat generated by the electrical and electronic components of this module. In particular, it has been proposed for the radiator or radiators to be exposed to the air flow generated in the casing, but by arranging the radiators at the casing outlet, which forces the components of the control module to be fairly distant from the motor that is to be controlled.
In addition, the presence of radiator fins penetrating into the air flow leaving the casing over a relatively great distance disturbs the flow and generates noise.
The purpose of the invention is to solve the problem of cooling the control module while at the same time maintaining the possibility of housing the module as maintaining the possibility of housing the module as close as possible to the motor, so as to reduce electrical connections and bulk, while at the same time allowing easy removal and easy refitting of the control module where necessary, and allowing this module to be cooled effectively.
This objective is achieved by virtue of a motor-fan unit of the type defined at the beginning of this description and in which the control module is mounted on the motor support cover on the outside thereof and the or each radiator for dissipating heat associated with the control module is at least partially engaged through at least one opening made in the motor support cover and opening laterally into the casing.
Thus, effective cooling can be obtained by exposing the radiator or radiators of the control module to the very turbulent air in the casing, while at the same time allowing easy removal and easy refitting of the control module because the latter, if need be, can be extracted from the motor-fan unit without the need to remove the motor support cover.
Advantageously, the control module comprises at least one radiator having several parts which are engaged through separate openings of corresponding shapes. Forming several openings, rather than a single opening which has necessarily to be larger, means that the rigidity of the motor support cover is not affected.
The or each radiator is engaged in at least one opening advantageously made in a region situated between an outer contour of the motor support cover and the central part of the latter situated facing the turbine. Thus, the or each radiator part projects laterally into the casing outside of the path of the turbine.
The distance by which the or each radiator part penetrates into the casing is therefore not limited by the need not to interfere with the turbine.
However, in order to avoid generating undesirable noise, this penetration distance may be relatively small, for example between 1 mm and 20 mm, preferably between 1 mm and 15 mm.
When the or each radiator penetrates at least partially by a short distance into the casing, or is even practically flush with the side thereof, a sufficient area for heat exchange with the air can be presented by increasing the dimensions, measured in the plane of the side of the casing, and thereby the dimensions of the opening or openings made in the motor support cover.
In a known way, the exchange area can also be increased by providing the or each radiator with reliefs of various shapes, such as ribs, for example curved, or pips.
Another subject of the invention is a heating and/or air conditioning apparatus comprising a motor-fan unit as defined hereinabove.